Autoimmune diseases, such as arthritis diseases in connective tissue disorders typified by rheumatoid arthritis cause, for example, dysfunction as a result of the progression of the destruction of cartilage and/or bone, and thus, this disease largely affects daily life.
To date, for the drug treatment of rheumatoid arthritis and other types of arthritis, nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and indomethacin, gold preparation, disease-modifying anti-rheumatoid drugs (DMARDs) such as D-penicillamine, steroidal drugs, and the like have been used. However, the progression of the destruction of cartilage and/or bone, which is the largest problem of arthritis, cannot be completely suppressed with the currently used treatment methods. Moreover, from the viewpoint of side effects, the aforementioned drugs cannot be used for a long period of time. Thus, these treatment methods have not yet provided a satisfactory treatment.
As a drug exhibiting effects on autoimmune diseases, immunosuppressing agents have been known (Non-Patent Document 1). The immunosuppressing agents suppress arthritis through inhibiting the production of antibodies, the production of cytokine, proliferation of lymphocyte, and the like. As such immunosuppressing agent, methotrexate and dexamethasone have been placed on the market, and even at present, the research and development of drugs are being performed.
On the other hand, benzophenone derivatives having an antiarthritic action have been known. It has been known that these benzophenone derivatives inhibit a transcription factor AP-1, and as a result, have an excellent anti arthritic action (Patent Document 1).
Moreover, a method of using several anti-arthritis agents in combination has been known (Non-Patent Document 2). However, the number of anti-arthritis agents for such combined use is limited, and thus, satisfactory therapeutic effects have not been achieved.
Furthermore, a method of using an immunosuppressing agent and a benzophenone derivative having an antiarthritic action in combination has not been known at all.